Biomedical subjects

Kurt Ulm

Publications and source records attributed to Kurt Ulm.

At least 19 recordsLinked to original sources

PubMed2006

The thymidylate synthase tandem repeat promoter polymorphism: A predictor for tumor-related survival in neoadjuvant treated locally advanced gastric cancer.

We evaluated DNA polymorphisms in the thymidylate synthase (TS) and 5,10-methylene-tetrahydrofolate reductase (MTHFR) genes for an association with response and survival in locally advanced gastric cancer treated with 5-FU based preoperative chemotherapy (CTx). DNA of 238 patients (CTx-group: total n = 135, completely resected (R0) n = 102; without CTx: R0 n = 103) was isolated from blood or from nontumorous tissues. In the CTx-group, genotyping of the tandem repeat and the G/C polymorphism in the triple repeat in the promoter region of the TS gene and of the C677T polymorphism of the MTHFR gene was performed. None of the TS or MTHFR genotypes were associated with histopathological response and only the TS tandem repeat polymorphism was significantly related to survival (all patients n = 135, p = 0.002; R0 resected patients n = 102, p = 0.007; log-rank test). Multivariate analysis revealed ypN (p < 0.001) and the TS tandem repeat polymorphism as independent prognostic factors in the CTx-R0-group (p = 0.003). Analyzing the prognostic significance of the TS polymorphisms in the R0-group without CTx, TS genotypes were not significantly associated with survival. Comparing survival between R0 patients with and without CTx in the respective TS genotype groups of the tandem repeat polymorphism, a significant survival benefit for the patients with CTx was found for the 2rpt/2rpt (n = 49; p = 0.002) and 2rpt/3rpt genotypes (n = 99; p = 0.004), but not for the 3rpt/3rpt genotype (n = 57; p = 0.93). Patients' survival after CTx was associated with the TS tandem repeat polymorphism. CTx did not improve survival of patients with the 3rpt/3rpt genotype. Thus, a different therapy might be more appropriate for these patients.

Adult↗

PubMed2006

Age-dependent effect of abciximab in patients with acute coronary syndromes treated with percutaneous coronary interventions.

BACKGROUND: No studies have specifically performed an age-based analysis of the efficacy of abciximab in patients with non-ST-segment elevation acute coronary syndromes undergoing percutaneous coronary intervention (PCI). The aim of the study was to assess whether there are age-dependent differences in the clinical benefit of abciximab in patients with acute coronary syndrome treated with PCI. METHODS AND RESULTS: We performed this retrospective analysis of 2022 patients with acute coronary syndrome enrolled in the Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment (ISAR-REACT 2) study and randomized to receive abciximab or placebo during a PCI procedure. The incidence of major adverse cardiac events (MACE) during the 30 days after PCI was the primary end point of the study. On the basis of the cutoff age value provided by logistic regression in connection with bootstrap resampling, patients were divided into those younger (n=1220) and older (n=802) than 70 years. Among younger patients, the incidence of MACE was 7.7% in the abciximab group versus 13.3% in the placebo group (relative risk 0.57, 95% confidence interval 0.40 to 0.80, P=0.001). In contrast, no difference was observed among older patients: The incidence of MACE was 10.9% in the abciximab group versus 9.9% in the placebo group (relative risk 1.10, 95% confidence interval 0.72 to 1.69, P=0.65). After adjustment for other variables, including cardiac troponin, there was a significant interaction between age and abciximab (P=0.04) with respect to MACE reduction, with abciximab being more effective in younger patients. CONCLUSIONS: In patients with non-ST-elevation acute coronary syndromes undergoing PCI, the efficacy of abciximab appears to be age-dependent, with greater benefit among younger patients.

Abciximab↗

PubMed2006

Simultaneous chemoradiotherapy compared with radiotherapy alone after induction chemotherapy in inoperable stage IIIA or IIIB non-small-cell lung cancer: study CTRT99/97 by the Bronchial Carcinoma Therapy Group.

PURPOSE: The aim of this study was to examine whether, after preceding induction chemotherapy, simultaneous chemoradiotherapy is superior to radiotherapy alone. PATIENTS AND METHODS: Patients with non-small-cell lung cancer in inoperable stage IIIA or IIIB received induction chemotherapy with two cycles of paclitaxel 200 mg/m2 and carboplatin area under the curve 6 every 3 weeks. Patients without progression at restaging after induction chemotherapy were randomly assigned to radiotherapy (60 Gy) or chemoradiotherapy (paclitaxel 60 mg/m2 weekly). The primary end point was overall survival; secondary end points were time to progression, response, and toxicity. RESULTS: Three hundred three patients entered the study, and 276 completed induction chemotherapy. Two hundred fourteen patients were randomly assigned (radiotherapy alone: n = 113; simultaneous chemoradiotherapy: n = 101). Median follow-up time of all randomly assigned patients was 13.6 months (interquartile range [IQR], 6.4 to 29.0 months), and median follow-up time of the subgroup of censored patients (n = 52) was 37.4 months (IQR, 5.9 to 57.0 months; maximum, 76.1 months). Toxicities during the induction phase were mild. During radiotherapy, overall toxicity rates were not significantly different between the two arms. Median survival times in the radiotherapy group and chemoradiotherapy group were 14.1 months (95% CI, 11.8 to 16.3 months) and 18.7 months (95% CI, 14.1 to 23.3 months; difference not statistically significant, P = .091). Median time to progression significantly favored simultaneous chemoradiotherapy (11.5 months; 95% CI, 8.3 to 14.7 months) versus radiotherapy alone (6.3 months; 95% CI, 5.0 to 7.6 months; P < .001, log-rank test). CONCLUSION: Induction chemotherapy followed by chemoradiotherapy with weekly paclitaxel is feasible. Response, time to progression, and survival favor chemoradiotherapy compared with radiotherapy alone.

Aged↗

PubMed2006

FGFR4 Arg388 allele is associated with resistance to adjuvant therapy in primary breast cancer.

PURPOSE: A recent study presented first evidence that a single nucleotide polymorphism (SNP) at codon 388 of fibroblast growth factor receptor 4 (FGFR4) gene, causing a transmembrane domain missense mutation (Gly388Arg), is associated with disease outcome in node-positive breast cancer. This article addresses the clinical relevance of this SNP, FGFR4 genotype, phenotype, and HER2 regarding patient outcome and influence of adjuvant systemic therapy in a substantial primary breast cancer collective (n = 372; median follow-up, 94.5 months). METHODS: Polymerase chain reaction restriction fragment length polymorphism analysis of germ-line polymorphism was performed in uninvolved lymph nodes; FGFR4 and HER2 expression were assessed immunohistochemically in tissue microarrays. RESULTS: In 51% of patients, homo- or heterozygous Arg388 allele was present. No correlation existed between FGFR4 genotype and expression or HER2 status. In node-negative patients, FGFR4 genotype was not correlated with disease outcome. In node-positive patients, however, FGFR4 Arg388 was significantly associated with poor disease-free survival (DFS; P = .02) and overall survival (OS; P = .04). Notably, this association seems to be attributable to relatively poor therapy response in Arg388 carriers, reflected in their significantly shorter DFS (P = .02) and OS (P = .045) among patients receiving adjuvant systemic therapy. It is also seen as a significant interaction term in a multivariate proportional hazards model with Arg388 carriers having only about half as much benefit from adjuvant systemic therapy as wild-type carriers. CONCLUSION: According to this study, FGFR4 Arg388 genotype is a marker for breast cancer progression in patients with adjuvant systemic therapy, particularly chemotherapy, and thus may indicate therapy resistance.

Adult↗

PubMed2006

Deceleration capacity of heart rate as a predictor of mortality after myocardial infarction: cohort study.

BACKGROUND: Decreased vagal activity after myocardial infarction results in reduced heart-rate variability and increased risk of death. To distinguish between vagal and sympathetic factors that affect heart-rate variability, we used a signal-processing algorithm to separately characterise deceleration and acceleration of heart rate. We postulated that diminished deceleration-related modulation of heart rate is an important prognostic marker. Our prospective hypotheses were that deceleration capacity is a better predictor of risk than left-ventricular ejection fraction (LVEF) and standard deviation of normal-to-normal intervals (SDNN). METHODS: We quantified heart rate deceleration capacity by assessing 24-h Holter recordings from a post-infarction cohort in Munich (n=1455). We blindly validated the prognostic power of deceleration capacity in post-infarction populations in London, UK (n=656), and Oulu, Finland (n=600). We tested our hypotheses by assessment of the area under the receiver-operator characteristics curve (AUC). FINDINGS: During a median follow-up of 24 months, 70 people died in the Munich cohort and 66 in the London cohort. The Oulu cohort was followed-up for 38 months and 77 people died. In the London cohort, mean AUC of deceleration capacity was 0.80 (SD 0.03) compared with 0.67 (0.04) for LVEF and 0.69 (0.04) for SDNN. In the Oulu cohort, mean AUC of deceleration capacity was 0.74 (0.03) compared with 0.60 (0.04) for LVEF and 0.64 (0.03) for SDNN (p<0.0001 for all comparisons). Stratification by dichotomised deceleration capacity was especially powerful in patients with preserved LVEF (p<0.0001 in all cohorts). INTERPRETATION: Impaired heart rate deceleration capacity is a powerful predictor of mortality after myocardial infarction and is more accurate than LVEF and the conventional measures of heart-rate variability.

Aged↗

PubMed2006

Efficient palliation in patients with small-cell lung cancer by a combination of paclitaxel, etoposide and carboplatin: quality of life and 6-years'-follow-up results from a randomised phase III trial.

PURPOSE: Based on the promising activity of paclitaxel in small-cell lung cancer (SCLC) we conducted a randomized phase III trial to evaluate whether a combination of paclitaxel, carboplatin and etoposide phosphate (TEC) improves survival and time to progression as well as tolerability and quality of life (QoL) compared to a regimen of carboplatin, etoposide phosphate and vincristine (CEV) in SCLC patients. PATIENTS AND METHODS: Six hundred and fourteen patients with stages I-IV SCLC were randomly assigned between January 1998 and December 1999 to both treatment arms. All patients were evaluated for response rate, survival, side effects and quality of life with overall survival (OS) serving as primary endpoint. A final analysis was done after a six-year follow-up. Survival curves were estimated using Kaplan-Meier curves and tested with the log-rank test. Quality of life data were assessed in using the EORTC QLQ-C30 questionnaire and evaluated by calculating and comparing the mean scores as well as applying longitudinal techniques. RESULTS: Six hundred and eight patients were evaluable for efficacy and toxicity. The long-term follow-up confirms the significant survival benefit for the paclitaxel, etoposide, carboplatin (TEC) regimen with a median OS of 12.5 months compared to 11.7 months for the CEV arm (HR, 1.21; 95% CI, 1.02-1.43; P=.030). The 5-year survival rates were 14% for the experimental versus 6 % for the CEV arm. Significant survival prolongation was also observed in the subgroup of patients with stage IV disease (HR, 1.27; 95% CI, 1.00-1.60; P=.047). The previously reported clinical benefit in form of an overall reduction of grade 3/4 toxicity was backed by the results of the comprehensive QoL analysis we report hereby. TEC significantly improves the relevant QoL parameters like global overall QoL or physical functioning. CONCLUSION: When administered in combination with etoposide and carboplatin, paclitaxel is able to offer in SCLC patients with extensive disease a survival benefit without additional toxicities, but with gains in patient-reported quality of life. In terms of efficient palliative care, TEC might be seen as an alternative to standard cisplatin plus etoposide in patients requesting a powerful palliative regimen not compromising any survival benefit.

Adolescent↗

PubMed2005

QRS duration and late mortality in unselected post-infarction patients of the revascularization era.

AIMS: To assess the association of prolonged QRS duration and late mortality in unselected post-infarction patients of the revascularization era. METHODS AND RESULTS: A total of 1455 survivors of acute myocardial infarction (MI) in sinus rhythm and under 76 years of age were enrolled. Ninety eight percent of the patients received reperfusion/revascularization therapy (90% percutaneous coronary intervention). After revascularization, prolonged QRS duration (>or=120 ms) was present in 87 patients (6.0%). Additional risk factors studied were age (>or=65 years), presence of diabetes mellitus, history of previous MI, mean heart rate (>75 b.p.m.), heart rate variability index (<or=20 U), arrhythmia on Holter, left ventricular ejection fraction (LVEF<or=30%), and heart rate turbulence (HRT). Primary endpoint was total mortality. During a follow-up period of 22+/-5 months, 70 patients died. On multivariable analysis, prolonged QRS duration showed the highest association with total mortality (hazard ratio 4.0; CI 2.3-6.9) followed by HRT Category 2 (3.8; 2.0-7.3) and LVEF<or=30% (3.1; 1.7-5.6). The association of prolonged QRS duration and late mortality was particularly strong in patients with LVEF<or=30% (5.0; 1.8-14.1). On multivariable analysis of secondary endpoints, prolonged QRS duration was significantly associated with cardiac mortality (3.9; 1.9-7.8), but not with sudden death and serious arrhythmic events. CONCLUSION: In the revascularization era, incidence of prolonged QRS duration is reduced. However, prolonged QRS duration is still highly correlated with increased late mortality.

Aged↗

PubMed2005

A non-parametric framework for estimating threshold limit values.

BACKGROUND: To estimate a threshold limit value for a compound known to have harmful health effects, an 'elbow' threshold model is usually applied. We are interested on non-parametric flexible alternatives. METHODS: We describe how a step function model fitted by isotonic regression can be used to estimate threshold limit values. This method returns a set of candidate locations, and we discuss two algorithms to select the threshold among them: the reduced isotonic regression and an algorithm considering the closed family of hypotheses. We assess the performance of these two alternative approaches under different scenarios in a simulation study. We illustrate the framework by analysing the data from a study conducted by the German Research Foundation aiming to set a threshold limit value in the exposure to total dust at workplace, as a causal agent for developing chronic bronchitis. RESULTS: In the paper we demonstrate the use and the properties of the proposed methodology along with the results from an application. The method appears to detect the threshold with satisfactory success. However, its performance can be compromised by the low power to reject the constant risk assumption when the true dose-response relationship is weak. CONCLUSION: The estimation of thresholds based on isotonic framework is conceptually simple and sufficiently powerful. Given that in threshold value estimation context there is not a gold standard method, the proposed model provides a useful non-parametric alternative to the standard approaches and can corroborate or challenge their findings.

Air Pollutants, Occupational↗

PubMed2005

Sirolimus-eluting stents vs paclitaxel-eluting stents in patients with coronary artery disease: meta-analysis of randomized trials.

CONTEXT: Placement of sirolimus-eluting stents or paclitaxel-eluting stents has emerged as the predominant percutaneous treatment strategy in patients with coronary artery disease (CAD). Whether there are any differences in efficacy and safety between these 2 drug-eluting stents is unclear. OBJECTIVE: To compare outcomes of sirolimus-eluting and paclitaxel-eluting coronary stents on the basis of data generated by randomized head-to-head clinical trials. DATA SOURCES: PubMed and the Cochrane Central Register of Controlled Trials, conference proceedings from major cardiology meetings, and Internet-based sources of information on clinical trials in cardiology from January 2003 to April 2005. STUDY SELECTION: Randomized trials comparing the sirolimus-eluting stent with the paclitaxel-eluting stent in patients with CAD reporting the outcomes of interest (target lesion revascularization, angiographic restenosis, stent thrombosis, myocardial infarction [MI], death, and the composite of death or MI) during a follow-up of at least 6 months. DATA EXTRACTION: Two reviewers independently identified studies and abstracted data on sample size, baseline characteristics, and outcomes of interest. DATA SYNTHESIS: Six trials, including 3669 patients, met the selection criteria. No significant heterogeneity was found across trials. Target lesion revascularization, the primary outcome of interest, was less frequently performed in patients who were treated with the sirolimus-eluting stent (5.1%) vs the paclitaxel-eluting stent (7.8%) (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.49-0.84; P = .001). Similarly, angiographic restenosis was less frequently observed among patients assigned to the sirolimus-eluting stent (9.3%) vs the paclitaxel-eluting stent (13.1%) (OR, 0.68; 95% CI, 0.55-0.86; P = .001). Event rates for sirolimus-eluting vs paclitaxel-eluting stents were 0.9% and 1.1%, respectively, for stent thrombosis (P = .62); 1.4% and 1.6%, respectively, for death (P = .56); and 4.9% and 5.8%, respectively, for the composite of death or MI (P = .23). CONCLUSIONS: Patients receiving sirolimus-eluting stents had a significantly lower risk of restenosis and target vessel revascularization compared with those receiving paclitaxel-eluting stents. Rates of death, death or MI, and stent thrombosis were similar.

Angioplasty, Balloon, Coronary↗

PubMed2005

Paclitaxel-eluting or sirolimus-eluting stents to prevent restenosis in diabetic patients.

BACKGROUND: Drug-eluting stents are highly effective in reducing the rate of in-stent restenosis. It is not known whether there are differences in the effectiveness of currently approved drug-eluting stents in the high-risk subgroup of patients with diabetes mellitus. METHODS: We enrolled 250 patients with diabetes and coronary artery disease: 125 were randomly assigned to receive paclitaxel-eluting stents, and 125 to receive sirolimus-eluting stents. The primary end point was in-segment late luminal loss. Secondary end points were angiographic restenosis (defined as in-segment stenosis of at least 50 percent at follow-up angiography) and the need for revascularization of the target lesion during a nine-month follow-up period. The study was designed to show noninferiority of the paclitaxel stent as compared with the sirolimus stent, defined as a difference in the extent of in-segment late luminal loss of no more than 0.16 mm. RESULTS: The extent of in-segment late luminal loss was 0.24 mm (95 percent confidence interval, 0.09 to 0.39) greater in the paclitaxel-stent group than in the sirolimus-stent group (P=0.002). In-segment restenosis was identified on follow-up angiography in 16.5 percent of the patients in the paclitaxel-stent group and 6.9 percent of the patients in the sirolimus-stent group (P=0.03). Target-lesion revascularization was performed in 12.0 percent of the patients in the paclitaxel-stent group and 6.4 percent of the patients in the sirolimus-stent group (P=0.13). CONCLUSIONS: In patients with diabetes mellitus and coronary artery disease, use of the sirolimus-eluting stent is associated with a decrease in the extent of late luminal loss, as compared with use of the paclitaxel-eluting stent, suggesting a reduced risk of restenosis.

Aged↗

PubMed2005

Characteristics of heart beat intervals and prediction of death.

OBJECTIVE: To assess the value for improving risk stratification of measures, unadjusted and adjusted for heart rate, of heart rate variability (HRV) and heart rate turbulence (HRT) based on 2- to 24-h ambulatory electrocardiographic recordings; and to relate this to the decision to use an implantable cardiac defibrillator (ICD) and the attendant consequences on effectiveness and cost-effectiveness. BACKGROUND: Risk stratification for high risk or low risk of lethal ventricular arrhythmic events, and hence for a decision about defibrillator implant, most commonly utilizes the left ventricular ejection fraction (LVEF). Electrocardiographic (ECG) approaches include 24-h ambulatory ECG recordings, with counts of ventricular premature contractions (VPCs), measures of heart rate variability (HRV), and heart rate turbulence (HRT). HRT has two components: turbulence onset (TO) and turbulence slope (TS). METHODS AND RESULTS: We evaluated the qualifying ambulatory ECG recordings from 744 patients in the active treatment arms of the Cardiac Arrhythmia Suppression Trial (CAST). Beat characteristics, VPC counts, normal-to-normal beat intervals, and time-domain measures of HRV and HRT were calculated. Tachograms were rescaled to a heart rate of 75 and the resulting "normalized" measures evaluated as risk predictors for death, compared to unnormalized measures. Measures based on 2-h ECGs were also evaluated as risk predictors. The most powerful univariate predictor of survival was the normalized turbulence slope. The best multivariate prediction model had six components: history of angina, hypertension, diabetes, and absence of post-myocardial infarction revascularization, the log of LVEF, normalized TS, HR, and an interaction term of HR and normalized TS. Gains in effectiveness from use of this model cost between $0 and $4000 per year of life saved. CONCLUSIONS: Turbulence slope substantially exceeded other ECG-based measures in improving prediction of subsequent death in models which included LVEF, and other clinical parameters. Use of this model would improve the effectiveness and cost-effectiveness of the ICD.

Arrhythmias, Cardiac↗

PubMed2005

Reduced prognostic power of ventricular late potentials in post-infarction patients of the reperfusion era.

AIMS: To test the prognostic value of ventricular late potentials (LPs) in a large cohort of post-infarction patients in the modern reperfusion era. METHODS AND RESULTS: 1800 consecutive survivors of acute myocardial infarction in sinus rhythm and under 76 years of age were enrolled. Many (99%) of the patients received reperfusion/revascularization therapy (91% percutaneous coronary intervention) and up-to-date pharmacological treatment (99% aspirin, 93% beta-blockers, 90% ACE-inhibitors, and 85% statins). LPs were calculated in 968 patients and found to be present in 90 (9.3%). The primary endpoint was the composite of cardiac death and serious arrhythmic events. The secondary endpoint was the composite of sudden cardiac death and serious arrhythmic events. During follow-up (median 34 months), 26 patients reached the primary endpoint. The presence of LPs was not significantly associated with the primary endpoint in univariable or multivariable analysis. In contrast, low (< or = 30%) left ventricular ejection fraction (hazard ratio 9.6, 95% confidence interval 4.1-22.4), heart rate turbulence category 2 (7.5, 2.4-23.9) and category 1 (5.3, 1.9-14.9) were significant predictors in both univariable and multivariable analysis. CONCLUSION: Ventricular LPs are of limited use for risk stratification in unselected post-infarction patients in the modern reperfusion era.

Aged↗

PubMed2004

Telomere length and human telomerase reverse transcriptase expression as markers for progression and prognosis of colorectal carcinoma.

PURPOSE: Maintenance of telomeres through reactivation of telomerase is a prerequisite for tumors to preserve their ability to proliferate. The purpose of this study was to evaluate telomere length and human telomerase reverse transcriptase (hTERT) expression as markers for progression and prognosis of colorectal carcinoma. PATIENTS AND METHODS: Telomere length and hTERT expression were analyzed in matched cancer and adjacent noncancer mucosa samples from 57 patients with R0-resected colorectal carcinoma. The median follow-up time was 76 months. RESULTS: Telomere length and hTERT expression correlated significantly in cancer tissues and adjacent mucosa samples (r = 0.52, P <.001; and r = 0.54, P <.001, respectively). Overall, cancer tissue had shorter telomeres than adjacent mucosa (P <.001). Only in noncancer tissue did telomere length decrease with age (r = 0.36; P <.01). Telomere length in cancer tissue was significantly correlated with tumor stage (P <.01), with longer telomeres in advanced tumors. Patients with ratios of telomere length in cancer to noncancer tissue greater than 0.90 had a significantly poorer overall survival compared with patients with smaller telomere length ratios (P <.002). In multivariate analysis, the telomere length ratio proved to be of independent prognostic value (P <.03). CONCLUSION: Telomeres in colorectal carcinoma tissue were significantly shorter compared with adjacent normal mucosa as an indication for extensive cell proliferation. The correlation with tumor stage and patient survival suggest that hTERT-mediated telomere stabilization may be critical for progression and prognosis of colorectal carcinoma.

Adult↗

PubMed2004

Structural relationships between measures based on heart beat intervals: potential for improved risk assessment.

Decreased left ventricular ejection fraction is the most commonly used risk factor for identification of patients at high-risk for lethal ventricular arrhythmic events. Twenty-four-hour electrocardiographic (ECG) approaches to risk stratification include: counts of ventricular premature contractions (VPCs), measures of heart rate variability (HRV), and heart rate turbulence (HRT) which has two components, turbulence onset and turbulence slope (TS). Refinement of these ECG risk stratifiers could enhance their clinical utility. We explored the structural relationships between heart rate (HR) and HRV and HRT measures. Our goal was to separate out the component of these measures due to the underlying average heart rate (HR), thus potentially reducing the variability of the measures and increasing their power to stratify risk. We proposed re-scaling tachograms of heart-beat intervals so that the re-scaled tachogram has a HR of 75 (or equivalently an average interval of 800 ms) and calculating HRV and HRT from the rescaled time series. We also explored the relationship between the number of VPCs and HRT. We showed that TS is structurally related to the number of VPCs (and hence to the length of the ECG recording). We proposed an adjusted TS that is independent of the number of VPCs. We also addressed the ability of shorter ECG recording to estimate HRV and HRT measures. We evaluated standard and rescaled HRV and HRT measures using qualifying ambulatory ECG recordings from 744 patients in the Cardiac Arrhythmia Suppression Trial. We found that measures based on the rescaled tachogram had reduced variance (20% to 40%). Correlations between measures were also substantially reduced. We also found substantial circadian effects on some, but not all HRV indices, not explained by the circadian pattern in HR and possibly pointing to additional measures for risk prediction. In conclusion, we found that adjusting for HR and the number of VPCs in heart-beat related ambulatory ECG measures has the potential to significantly improve the power of these measures to risk stratify cardiac patients.

Algorithms↗

PubMed2003

Risk stratification after acute myocardial infarction by heart rate turbulence.

BACKGROUND: Retrospective postinfarction studies revealed that decreased heart rate turbulence (HRT) indicates increased risk for subsequent death. This is the first prospective study to validate HRT in a large cohort of the reperfusion era. METHODS AND RESULTS: One thousand four hundred fifty-five survivors of an acute myocardial infarction (age <76 years) in sinus rhythm were enrolled. HRT onset (TO) and slope (TS) were calculated from Holter records. Patients were classified into the following HRT categories: category 0 if both TO and TS were normal, category 1 if either TO or TS was abnormal, or category 2 if both TO and TS were abnormal. The primary end point was all-cause mortality. During a follow-up of 22 months, 70 patients died. Multivariately, HRT category 2 was the strongest predictor of death (hazard ratio, 5.9; 95% CI, 2.9 to 12.2), followed by left ventricular ejection fraction (LVEF) < or =30% (4.5; 2.6 to 7.8), diabetes mellitus (2.5; 1.6 to 4.1), age > or =65 years (2.4; 1.5 to 3.9), and HRT category 1 (2.4; 1.2 to 4.9). LVEF < or =30% had a sensitivity of 27% at a positive predictive accuracy level of 23%. The combined criteria of LVEF < or =30%, HRT category 2 or LVEF >30%, age > or =65 years, diabetes mellitus, and HRT category 2 had a sensitivity of 24% at a positive predictive accuracy level of 37%. The combined criteria of LVEF < or =30% or LVEF >30%, age > or =65 years, diabetes mellitus, and HRT category 1 or 2 had a sensitivity of 44% at a positive predictive accuracy level of 23%. CONCLUSIONS: HRT is a strong predictor of subsequent death in postinfarction patients of the reperfusion era.

Aged↗

PubMed2003

Randomized phase III trial of paclitaxel, etoposide, and carboplatin versus carboplatin, etoposide, and vincristine in patients with small-cell lung cancer.

BACKGROUND: Paclitaxel administered in combination with a topoisomerase-II inhibitor (such as etoposide) and carboplatin is an effective and safe first-line treatment for patients with small-cell lung cancer (SCLC). We conducted a randomized phase III multicenter trial to determine whether paclitaxel plus etoposide plus carboplatin improves the outcome of patients with primary SCLC relative to standard chemotherapy (carboplatin, etoposide, and vincristine). METHODS: Between January 1998 and December 1999, 614 patients with SCLC stages I-IV were randomly assigned to the standard arm (309 patients) or the experimental arm (305 patients). Treatment courses were repeated every 21 days for a maximum of six courses. All patients were evaluated for response rate, survival, and toxicities every two courses. The primary endpoint was survival. Survival curves were estimated with the Kaplan-Meier method and compared using the log-rank test. All statistical tests were two-sided. RESULTS: A total of 608 patients were evaluable for all endpoints (standard arm 307 patients, experimental arm 301 patients). The hazard ratio [HR] of death for patients receiving the standard treatment was statistically significantly higher than that for patients receiving the experimental treatment (HR = 1.22, 95% confidence interval [CI] = 1.03 to 1.45; P =.024). Progression-free survival was also statistically significantly shorter for patients in the standard arm relative to that of patients in the experimental arm (HR = 1.21, 95% CI = 1.03 to 1.42). There were no differences in the response rates (complete and partial combined) to the treatments (standard arm: 69.4%, 95% CI = 63.9% to 74.5%; experimental arm: 72.1%, 95% CI = 66.7% to 77.1%; difference = 2.7%, 95% CI = 4.5% to 9.9%). Rates of severe grade of anemia, leukocytopenia, neutropenia, and thrombocytopenia were lower in the experimental arm than in the standard arm. CONCLUSION: Patients with previously untreated SCLC who received paclitaxel, etoposide, and carboplatin showed improved overall and progression-free survival and less frequent hematologic toxicities than those who received the standard therapy.

Adult↗

PubMed2003

Dynamic Cox modelling based on fractional polynomials: time-variations in gastric cancer prognosis.

The most popular model used for survival analysis is the proportional hazards regression model proposed by Cox. This is mainly due to its exceptional simplicity. Nevertheless the fundamental assumption of the Cox model is the proportionality of the hazards. For many applications, however, this assumption is doubtful. Proposals to extend the Cox model for non-proportional hazards to allow for dynamic effect structures usually either depend on prespecifications or require non-standard estimation techniques and are thus not favoured in application. Moreover, tests to verify the dynamic effect structures are not straightforward or lack omnibus power. In this paper we propose a flexible method for modelling dynamic effects in survival data within the Cox framework. The method is based on fractional polynomials as introduced by Royston and Altman. This allows for a transformation of the dynamic predictor which leads back to the conventional Cox model and hence fitting is straightforward using standard estimation techniques. In addition, it offers the possibility of easily verifying the existence of time-variation. We describe a model selection algorithm which selects time-varying effects only when evidence is given in the data. We illustrate the properties of the approach in a simulation study and compare it with other methods. In a survival study of gastric cancer patients, we apply the approach to analyse dynamic structures in the effects of prognostic factors.

Adult↗

PubMed2003

Effects of functional Toll-like receptor-4 mutations on the immune response to human and experimental sepsis.

Genetically determined responsiveness to microbial stimuli such as lipopolysaccharide (LPS) may affect the pathophysiology of human sepsis. The D299G mutation in human Toll-like receptor-4 (TLR4) impairs LPS signalling in homozygous and heterozygous individuals. To investigate whether the presence of the TLR4(D299G) mutation may correlate with the development or outcome of sepsis following major visceral surgery the presence of TLR4(D299G) mutation was analysed in 307 Caucasian patients (154 without and 153 with sepsis). Sepsis was caused in 84% of patients by polymicrobial infection. The presence of the mutant TLR4 did not significantly correlate with development or outcome of sepsis. Serum levels of tumour necrosis factor, interleukin (IL)-10, and IL-6 at sepsis onset did not significantly differ between patients carrying wild-type and mutant TLR4. Moreover, studies in a murine model of polymicrobial septic peritonitis demonstrated that TLR4-deficiency did neither influence the systemic cytokine response nor the development of organ injury. The results suggest that the signalling capacity of TLR4 as affected by loss-of-function mutations does not influence human or experimental sepsis caused by polymicrobial infection. Thus, in polymicrobial infection, other innate immune receptors may compensate for TLR4 defects.

Aged↗